JP3470077B2 - Discharge light emitting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a discharge light emitting device in which a discharge gas such as xenon is sealed between electrodes and emits light by gas discharge between the electrodes.

[0002]

2. Description of the Related Art Conventionally, various light emitting devices have been devised,
It is used as a light source. One of them is a contact image sensor (CIS: Contact) that reads contents such as figures.
Some are used as a light source for ImageSensor).

FIG. 11 and FIG. 12 show an example of a CIS 100 incorporating a conventional light source. FIG. 11 shows JP-A-4
FIG. 12 is a plan view of the CIS 100 disclosed in Japanese Patent No. -360458 (Japanese Patent No. 2953595), and FIG. 12 is a cross-sectional view of the CIS 100 shown in FIG. 11.

As shown in FIGS. 11 and 12, the CIS
100 is a light emitting diode (LED: Light) as a light source.
A t emitting diode) array 101, a housing 102, a sensor IC (Integrated circuit) 103, a rod lens array 104, and a glass plate 105.

The platen 10 is provided by the LED array 101.
7 is irradiated with light, and reflected light passes through the rod lens array 104 and reaches the sensor IC 103. And this sensor IC
The reflected light is converted into an electric signal by 103, and the original 106
The content of is read.

[0006]

However, the use of the LED array 101 as the light source of the contact image sensor as described above causes various problems as described below.

When an LED is used as a light source, the required light quantity of the light source changes in the line sensor depending on the time when the image sensor reads one line. This means that the signal output I of the sensor has a relationship of I∝T × B with respect to the reading speed (reading time T per line T) and the brightness B of the light source. Therefore, the LED array 101
However, when the reading time T is long (a reading of a document such as a facsimile is -10 ms / line), an output from the sensor that does not cause a problem in use can be obtained.

However, for high-speed reading of 0.5 ms / line or less, the reading time T becomes very short, and there is a problem that a sufficient sensor output cannot be obtained.

When LED chips are arranged, LE
The light output of the D chip has a strong directivity, and the amount of light to the front and the amount of light to the diagonal front are greatly different, so that the following problem also occurs. First, when a line light source is manufactured by arranging LED chips, due to restrictions on the mounting pitch, LEDs
Since there is a gap between the chips, a light amount difference occurs between the LED chip and the gap. Therefore, undulation of the light amount at the LED mounting pitch occurs in the arrangement direction of the LED chips.

Further, the above-mentioned waviness is further increased due to variations in the mounting accuracy of the LEDs (the accuracy with which the emission centers of the LEDs are arranged on one line) and the above-mentioned directivity of the light amount.

Further, there is a large variation in the brightness of the LED chips themselves, and by arranging the LED chips, the variation in the brightness becomes a brightness distribution on the line. Therefore, there is also a problem that it is difficult to obtain a uniform light amount over the entire length of the illumination.

In order to obtain high brightness, it is necessary to mount the LED chips at a high density and increase the current that contributes to the light emission. However, both of them cause heat generation of the light source, which shortens the life of the LED chips.

As the light source of the CIS, there are cases where a cylindrical lamp which has been used as a conventional illumination such as a hot cathode tube (fluorescent lamp) or a cold cathode tube is used. In this case, a sufficient amount can be obtained as the brightness of the light source.

However, the internal shape of the CIS must be a shape that can accommodate a cylindrical light source, and the sectional shape becomes large. Further, since such a lamp has electrodes at both ends, a portion having a low brightness called a cathode dark portion is always generated for several cm. Therefore, there arises a problem that the ratio of a region where the amount of light is stable to the entire length of the light source becomes small.

Therefore, the inventors of the present invention have made extensive studies and have conceived to use a light source of a type that emits light by discharge as a light source of a contact image sensor, and succeeded in developing such a light source. FIG. 1 shows a structural example of a discharge light emitting device 1 that can be used as the light source.

As shown in FIG. 1, the discharge light emitting device 1 includes a substrate 2, a transparent substrate 3, an internal electrode 4, an external electrode 5, and
Metal bus bar 6, insulating layer (dielectric layer) 7, and first phosphor 8
And a second phosphor 9, a sealing layer 10, and a discharge space 11.

The substrate 2 and the transparent substrate 3 are made of glass or the like, for example. The transparent substrate 3 is superposed on the substrate 2 and has a wall portion 3 a extending toward the substrate 2. The wall 3 a is connected to the substrate 2 via the sealing layer 10 and the insulating layer 7. Thereby, the discharge space 11 is formed between the substrate 2 and the transparent substrate 3. A discharge gas such as xenon is enclosed in the discharge space 11. Incidentally, the sealing layer 10
Is composed of, for example, a glass layer formed by melting a frit.

The internal electrode 4 is formed on the substrate 2 and covered with an insulating layer 7. The insulating layer 7 is composed of, for example, a glass layer. Forming a first phosphor 8 on the insulating layer 7,
The second phosphor 9 is formed on the surface of the transparent substrate 3.

The external electrode 5 is made of, for example, ITO (Indium Ti
n Oxide), SnO _2, etc., and has a light-transmitting property. The external electrode 5 is formed on the outer surface of the transparent substrate 3, and the metal bus bar 6 is formed on the peripheral portion of the external electrode 5.

To cause the discharge light emitting device 1 having the above structure to emit light, a predetermined voltage (for example, about 1000 V) is applied between the inner electrode 4 and the outer electrode 5. Thereby,
The discharge gas is ionized to emit ultraviolet rays, and the ultraviolet rays irradiate the first and second phosphors 8 and 9, and the first and second phosphors 8 and 9 emit light.

The brightness of the light thus obtained is LE
The inventors of the present application have confirmed that it is higher than that of the conventional example using D. Further, the luminance distribution was uniform, and the life of the discharge light emitting device 1 was significantly longer than that of the LED. Further, the ratio of effective illumination length can be considerably increased, and size reduction in the longitudinal direction is facilitated. Moreover, since no harmful substances such as mercury are used, environmental damage can be avoided.

As described above, according to the discharge light emitting device 1 shown in FIG. 1, various effects superior to the conventional example can be obtained.
The inventors of the present application further researched, and discovered the following new problems with the discharge light emitting device 1. The problem will be described below.

FIG. 2 shows a discharge path 12a in the discharge space 11 when the discharge light emitting device 1 emits light. The arrow in FIG. 2 indicates the direction of light emission.

As shown in FIG. 2, since the internal electrode 4 and the external electrode 5 are arranged so as to face each other, the discharge path 12a faces the direction perpendicular to the main surfaces of the substrates 2 and 3. Therefore, the length of the discharge path 12a becomes the shortest distance between the substrates 2 and 3 and becomes short.

However, in general, in a light source using gas discharge, the longer the discharge path length, the higher the brightness and the luminous efficiency. Therefore, there is a problem in that the discharge path length is shortened as described above, and thus the luminance and the luminous efficiency of the discharge light emitting device 1 are reduced.

The present invention has been made to solve the above problems. The object of the present invention is to improve the brightness, to make the brightness distribution uniform, to have a long life, to increase the ratio of effective illumination length, to facilitate the size reduction in the longitudinal direction, and to avoid environmental damage. Another object of the present invention is to provide a discharge light-emitting device that can achieve higher light emission efficiency.

[0027]

The discharge light emitting device according to the present invention comprises first and second substrates, first and second phosphors, and first and second electrodes. The second substrate is the first
It is transparent on the first substrate so as to form a discharge space in which a discharge gas is enclosed between the substrate and the substrate. The first and second phosphors are installed in the discharge space. The first electrode is provided on the first substrate side, and the second electrode is provided on the second substrate side. Then, the second electrode is displaced from the first electrode so that the first electrode and the second electrode do not overlap with each other.

By arranging the second electrode so as to be offset from the first electrode in this way, the discharge path can be tilted by a predetermined angle from the direction perpendicular to the main surfaces of the first and second substrates. That is, the discharge path can be directed obliquely to the main surfaces of the first and second substrates. Thereby, the discharge path length (discharge gap) can be made longer than that in the example shown in FIG. 1, and the luminance and the light emission efficiency can be improved.
Further, since discharge light emission is generated in the direction in which the first electrode and the second electrode are connected, a light emitting region is less likely to occur immediately below the electrode,
All emitted light can be taken out. This can also contribute to the improvement of luminous efficiency. Further, when the discharge light is extracted by utilizing the discharge, generally, the smaller the current density flowing during the discharge, the higher the luminous efficiency. Therefore,
As described above, by arranging the second electrode so as to be offset from the first electrode, strong discharge occurs in the direction in which the first electrode and the second electrode are connected, but weak discharge occurs in other regions. . Therefore, the current density has a distribution, a region having a low current density is generated, and the luminous efficiency can be improved as a whole.

The first substrate has a first phosphor and the second substrate has a second phosphor. At this time, the thickness of the first phosphor is larger than the thickness of the second phosphor. Thereby, light can be emitted through the second substrate.

The first electrode is arranged on the surface of the first substrate on the side of the discharge space, and the second electrode is arranged on the outer surface of the second substrate opposite to the side of the discharge space. in this case,
The second electrode has a ground potential.

In this way, there is a possibility of contact with the outside
By setting the electrode to the ground potential, it is possible to avoid touching the second electrode and receiving an electric shock, thus ensuring work safety. In addition, when the casing of the discharge light emitting device is set to the ground potential, the casing and the second
This eliminates the need for insulation design with the electrodes, thus avoiding complication of the structure and enlargement of the housing. In addition, EMI from the light extraction part
It is also possible to have a shielding effect against (radiation noise). The number of driving cycles for light emission is 50 KHz to 100
Since it is KHz and its wavelength is longer than the aperture of the light source (discharge light emitting device), the shielding effect can be expected even with such a structure.

The second substrate preferably has a wall portion (spacer) extending toward the first substrate, and the second electrode is preferably arranged inside the wall portion of the second substrate.

When a substance having a large relative permittivity other than the discharge gas exists between the electrodes, a capacitor is formed between the substance and the electrodes. This capacitor has a larger capacity than the discharge gas space. When a voltage that causes light emission is applied from the outside, the charge that does not contribute to light emission that charges the above capacitor is larger than the charge that charges the discharge space to raise the voltage, and the overall efficiency (input The ratio of the amount of light to electric power) decreases. here,
Since the relative permittivity of the wall portion is large, by arranging the second electrode inside the wall portion, it is possible to avoid applying a voltage to the wall portion and prevent a decrease in efficiency. You can As a result, the power that is ineffective for light emission can be reduced, and the light emission efficiency can be improved.

The first electrode may be arranged on the outer surface of the first substrate opposite to the discharge space side, and the second electrode may be arranged on the discharge space side surface of the second substrate. In this case, the first electrode is set to the ground potential.

It is preferable to provide an insulating layer having a light-transmitting property and covering the second electrode. Thereby, light can be emitted to the outside through the insulating layer.

An opening reaching the second substrate may be provided in the insulating layer, and the second phosphor may be formed on the surface of the second substrate located in the opening.

When the light is emitted from the insulating layer side to the outside, by providing the above-mentioned opening, the light can be emitted to the outside through this opening. Thereby, the brightness can be improved as compared with the case where light is emitted to the outside through the insulating layer. Further, it is not necessary to improve the transparency of the insulating layer.

A wall portion extending toward the second substrate may be provided on the first substrate side. In this case, the first electrode is arranged inside the wall of the first substrate. Also in this case, the luminous efficiency can be improved.

The first electrode has a flat plate shape (strip shape) and the second electrode has a ring shape. In this case, discharge is generated on both sides of the first electrode, and the brightness and the luminous efficiency can be further improved. Further, since discharge light emission is generated in a region surrounded by the annular second electrode, it is difficult to generate a light emitting region directly below the electrode, and all the light emission can be taken out to the outside. Further, also in this case, a region having a low current density can be positively generated, and the luminous efficiency can be improved as a whole. Further, even if one side of the second electrode is broken, the second electrode does not become defective and the margin for the breaking of the electrode can be improved. In addition, the light outlet can be clearly defined by the second electrode.

The discharge light emitting device according to the present invention is particularly useful as a light source for a contact image sensor.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 3 is a sectional view showing a discharge light emitting device 1 according to the present invention. It should be noted that the same components as those in the example shown in FIG.

As shown in FIG. 3, in the discharge light emitting device 1 according to the present embodiment, the external electrode 5 shown in FIG. 1 is omitted,
The external electrode 13 is newly provided. This external electrode 13
Are selectively formed on the outer surface of the transparent substrate 3 (the surface located on the side opposite to the discharge space 11 side) and are set to the ground potential.

As described above, since the light transmittance of the external electrode 5 shown in FIG. 1 is about 80%, by omitting the external electrode 5, an efficiency of about 20% is obtained as compared with the case shown in FIG. Can be improved.

The external electrode 13 is made of, for example, Cu, Al, A.
It is composed of a metal such as g, Au, Ni or a mixture thereof, and has an annular shape as shown in FIG. The outer peripheral shape of the external electrode 13 is typically rectangular, but any other shape can be selected. The external electrode 13 may be adhered to the transparent substrate 3 via an adhesive layer (not shown), but the external electrode 13 is covered with an adhesive transparent sheet (not shown), and this sheet is attached to the transparent substrate 3 The external electrode 13 may be attached to the transparent substrate 3 by attaching the external electrode 13 to the transparent substrate 3.

As shown in FIG. 3, the external electrode 13 has a wall portion 3.
It is arranged inside a and is located on the outer periphery of the external electrode 13 and the substrate 3.
Is separated from the wall portion 3a. Specifically, the external electrode 1
A distance D4 between the outer periphery of the wall 3 and the wall 3a is preferably 0.5 mm or more. By separating the outer periphery of the external electrode 13 from the wall portion 3a in this manner, it is possible to suppress application of a voltage to the wall portion 3a and avoid ineffective power consumption.

The internal electrode 4 is the discharge space 1 in the substrate 2.
It is formed on the surface on the first side and has a width smaller than that shown in FIG. Thereby, a gap can be provided in the horizontal direction between the inner circumference of the outer electrode 13 and the outer circumference of the inner electrode 4, and the outer electrode 13 and the inner electrode 4 can be prevented from overlapping. That is, the external electrode 13 and the internal electrode 4
And can be horizontally offset from each other.

As a result, the discharge path 12b can be oriented obliquely to the main surface of the substrate 2, the length of the discharge path can be increased, and the luminous efficiency can be improved.
Further, since the light emitting region can be arranged in the region surrounded by the external electrode 13, the ultraviolet light generated by the discharge can be effectively used.

When the discharge light is extracted by utilizing discharge, it is known that the smaller the current density flowing during discharge, the higher the luminous efficiency. In the structure shown in FIG. 1, the current density during discharge is uniform, and in order to change the size,
The voltage applied from the outside may be changed. However, in the structure shown in FIG. 1, when the applied voltage was lowered to reduce the current density, the discharge became unstable, and a phenomenon in which uniform light emission could not be obtained occurred. Therefore, the minimum applied voltage is limited.

On the other hand, by disposing the external electrode 13 and the internal electrode 4 so as to be offset from each other as described above, a strong discharge is generated in the direction in which the external electrode 13 and the internal electrode 4 are connected,
In other regions, the discharge becomes weak. Therefore, the current density can be distributed, and a region having a low current density can be positively provided. As a result, the luminous efficiency can be improved as a whole.

If the discharge path length can be increased, for example, as shown in FIG. 6, the external electrode 13 is arranged near the right end of the transparent substrate 3 and the left end of the substrate 2 is arranged. The internal electrode 4 may be arranged in the vicinity. Thereby, the discharge path length can be further increased as compared with the case shown in FIG.

Next, the inventors of the present invention have found a preferable relationship between the distance D2 between the external electrode 13 and the internal electrode 4, the width D3 of the internal electrode 4, and the height H of the discharge space 11.
The contents will be described.

Specifically, the distance D2 and the height H are D2 ≧
It is preferable to satisfy the relationship of (H / 2). The basis for this will be described below with reference to FIG. In FIG. 5, the height H is 1
It is a figure which shows the relationship of the space | interval D2 between the external electrode 13 and the internal electrode 4, the width D3 of the internal electrode 4, and relative efficiency in case of being mm.

As shown in FIG. 5, the distance D2 is 0.5 m.
When the m and the width D3mm are 1.0, the relative efficiency becomes maximum,
It can be seen that the relative efficiency decreases as the outer electrode 13 and the inner electrode 4 overlap. From this result, it is considered that the relative efficiency can be improved by setting the distance D2 to 0.5 mm or more when the height H is 1 mm, that is, by satisfying the relationship of D2 ≧ (H / 2). To be

The distance D1 between the external electrodes 13 is D1.
= 2 × D2 + D3, 2m when the relative efficiency is maximum
m. That is, when the relative efficiency is maximum, the distance D1
Is twice the height H.

Next, the first and second phosphors 8 and 9 will be described.
Explain. Usually, the emission color of the light source is excited by vacuum ultraviolet light
It depends on the phosphor to be used. For example, green-yellow
LaPO for high brightness light source_Four: Ce, Tb based fluorescence
Green and yellow phosphors and red phosphors ((Y,
Gd, Eu) BO₃, (Y, Gd, Eu)₂O₃Etc.),
Blue phosphor ((Ba, Eu) MgAl_TenBO₁₇, (S
r, Ca, Ba, Mg)_TenCl₂: Eu, Sr_Ten(P
O_Four) Cl₂: Eu, etc.) and a green phosphor ((Zn₂Si
O ₂: Mn, (Zn, Mg)₂SiO₂Etc.) and
It

The particle diameter of the above-mentioned phosphor is about 2 to 10 μm, and the portion that emits ultraviolet light is only the surface layer portion of the particle. Therefore, when a phosphor is formed, its film thickness and particle density are important parameters that determine the emission intensity.

As shown in FIG. 3, in the discharge light-emitting device 1 of the present invention, the first phosphor 8 which is formed on the substrate 2 located on the back side and emits light to the transparent substrate 3 side, and the transparent material which is located on the front side. A second phosphor 9 is provided which is formed on the substrate 3 and which transmits light and also emits light by itself.

Then, the inventors of the present application made the first and second
The relationship between the thickness of the phosphors 8 and 9 and the relative brightness was also examined. The results will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram showing the relationship between the thickness of the first and second phosphors 8 and 9 and the relative brightness. FIG. 10 shows the first
And the thickness of the second phosphors 8 and 9 and the thickness of the insulating layer 7,
It is a figure which shows the relationship with relative efficiency.

As shown in FIG. 9, it can be seen that the thickness of the first and second phosphors 8 and 9 affects the relative brightness. That is, it can be seen that the relative brightness can be maintained high when the thicknesses of the first and second phosphors 8 and 9 are within the predetermined range.

Specifically, the thickness of the first phosphor 8 is preferably 40 μm or more and 60 μm or less, and the thickness of the second phosphor 9 is preferably 3 μm or more and 10 μm or less. More preferably, the thickness of the first phosphor 8 is 50 μm.
m, and the thickness of the second phosphor 9 is 5 μm. Thereby, the brightness of the discharge light emitting device 1 can be improved.

As shown in FIG. 10, the second phosphor 9
It can be seen that the smaller the thickness, the higher the efficiency, and the thicker the first phosphor 8 and the insulating layer 7, the higher the efficiency.

Specifically, regarding the second phosphor 9, in consideration of the particle diameter of the phosphor, the feasibility, etc., as described above, 5 μm is used.
It is preferably about m. However, even if the thickness of the second phosphor 9 is about 10 μm, as shown in FIG.
The efficiency is not so low. Therefore, as described above, the thickness of the second phosphor 9 may be 10 μm or less.

Since the first phosphor 8 is not as dense as the insulating layer 7, there is not much change in the discharge voltage due to the change in film thickness.
The larger the film thickness of the phosphor 8, the higher the brightness. But,
Even if the film thickness of the first phosphor 8 is set to 40 μm or more, the degree of efficiency improvement does not increase so much, and therefore the value may be set to this value or more.

Regarding the insulating layer 7, the thicker it is, the more effectively the internal electrode 4 can be protected. But,
Since the voltage increased as the thickness of the insulating layer 7 increased, it is preferable that the thickness of the insulating layer 7 be about 50 μm or less as a realistic value. If the insulating layer 7 is too thin, it may cause dielectric breakdown. Therefore, the thickness is preferably 30 μm or more. The insulating layer 7 has a thickness of 30 μm.
If it is m or more, the internal electrode 4 can be effectively protected.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 7 and 8. Figure 7
FIG. 4 is a sectional view of a discharge light emitting device 1 according to a second embodiment of the present invention. FIG. 8 is a sectional view of a modification of the discharge light emitting device 1 shown in FIG.

As shown in FIG. 7, this embodiment is similar to FIG.
The discharge light emitting device 1 shown in FIG. More specifically, the substrate on the internal electrode 4 side is the transparent substrate 3
The external electrode 13 is formed on the substrate 20 side.

In the first embodiment described above, it is practical that the external electrode 13 is formed after the substrate 2 and the transparent substrate 3 are bonded together. The discharge light-emitting device 1 has an elongated shape, and it is difficult to position the external electrode 13 that is a thin electrode pattern on such an elongated structure, whether the electrode is formed by printing or when it is attached by tape or the like. Is. However, since the external electrode 13 also plays a role of a window when emitting light to the outside, its positional accuracy is important.

Therefore, in the present embodiment, the internal electrode 4
Are collectively formed on the transparent substrate 30 by printing,
Other elements are positioned with reference to the transparent substrate 30. This facilitates positioning of each element. Further, since the external electrode 13 has a strip shape and does not play a role of a window for light, positioning in operation becomes easy.

Further, the inner electrode 4 has a ring shape, and the outer electrode 1
3 is a flat plate shape. The wall portion 20a is provided on the substrate 20 side. The external electrode 13 is arranged inside the wall portion 20a and is set to the ground potential also in the present embodiment.

In this embodiment, as shown in FIG. 7, emitted light is transmitted through the insulating layer 7, so the insulating layer 7 is made of a material having a light transmitting property. As the insulating layer 7, printing glass or the like can be used.

Next, a modification of the discharge light emitting device 1 shown in FIG. 7 will be described with reference to FIG. As shown in FIG.
An opening 14 reaching the transparent substrate 30 may be provided in the insulating layer 7, and the first phosphor 8 may be formed on the surface of the transparent substrate 30 located in the opening 14.

By providing the opening 14 as described above, light can be emitted to the outside through the opening 14. This eliminates the need to improve the transparency of the insulating layer 7.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments.

For example, the internal electrode 4 and the external electrode 13 may be arranged in any other arrangement than the above as long as they do not overlap. Further, the shapes of the internal electrode 4 and the external electrode 13 may be arbitrary shapes other than the above. Further, the discharge light emitting device according to the present invention is useful as a light source for a contact image sensor,
It can also be used for other purposes.

[0076]

As described above, according to the discharge light emitting device of the present invention, the brightness of the emitted light becomes high, the brightness distribution becomes uniform, the life is long, and the ratio of the effective illumination length can be increased. In addition, size reduction in the longitudinal direction is facilitated, environmental damage can be avoided, and luminous efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a discharge light emitting device devised by the present inventors.

FIG. 2 is a cross-sectional view showing a state in which the discharge light emitting device of FIG. 1 is emitting light.

FIG. 3 is a cross-sectional view of the discharge light emitting device according to the first embodiment of the present invention.

FIG. 4 is a plan view of the discharge light emitting device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between relative efficiency, an interval between electrodes, and an electrode width of an internal electrode.

6 is a cross-sectional view of a modification of the discharge light emitting device shown in FIG.

FIG. 7 is a sectional view of a discharge light emitting device according to a second embodiment of the present invention.

8 is a cross-sectional view of a modified example of the discharge light emitting device shown in FIG.

FIG. 9 is a diagram showing a relationship between relative luminance and the thickness of a phosphor.

FIG. 10 is a diagram showing a relationship between relative efficiency and thicknesses of a phosphor and an insulating layer.

FIG. 11 is a plan view of a conventional CIS.

12 is a cross-sectional view of the CIS shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Discharge light emitting device, 2,20 substrate, 3,30 transparent substrate, 3a, 20a wall part, 4 internal electrode, 5,13 external electrode, 6 metal bus bar, 7 insulating layer (dielectric layer), 8
1st fluorescent substance, 9 2nd fluorescent substance, 10 sealing layer, 11 discharge space, 12a, 12b discharge path, 14 opening.

Claims (7)

(57) [Claims] 1. A first substrate, and a second substrate having a translucency and superposed on the first substrate so as to form a discharge space in which a discharge gas is enclosed between the first substrate and the first substrate. A first electrode provided on the first substrate side, a second electrode provided on the second substrate side, and a first electrode provided on the first substrate side; And the second electrode are arranged so as not to overlap with each other, the second electrode is displaced from the first electrode , the first substrate has the first phosphor, and the second substrate has the second fluorescence. And a thickness of the first phosphor is greater than a thickness of the second phosphor.
Ki, discharge light emitting device. 2. A first substrate, a discharge space into which a discharge gas is sealed between the first substrate
Is formed on the first substrate so as to form a transparent film.
A second substrate, first and second phosphors installed in the discharge space, a first electrode provided on the first substrate side, and a second electrode provided on the second substrate side. the provided, such that the first and second electrodes do not overlap, the first electrode
The second electrode is displaced with respect to the first substrate , and the second electrode is arranged on the surface of the first substrate on the discharge space side.
1 electrode is arranged and is located on the side opposite to the discharge space side on the second substrate.
A discharge light emitting device , wherein the second electrode is disposed on an outer surface of the second electrode, and the second electrode is at a ground potential . 3. A first substrate, a discharge space into which a discharge gas is sealed between the first substrate
Is formed on the first substrate so as to form a transparent film.
A second substrate, first and second phosphors installed in the discharge space, a first electrode provided on the first substrate side, and a second electrode provided on the second substrate side. the provided, such that the first and second electrodes do not overlap, the first electrode
The second electrode is arranged to be offset with respect to the second substrate, and the second substrate has a wall portion extending toward the first substrate.
And having the second electrode disposed inside the wall portion of the second substrate
A discharge light emitting device. 4. A first substrate, a discharge space into which a discharge gas is sealed between the first substrate
Is formed on the first substrate so as to form a transparent film.
A second substrate, first and second phosphors installed in the discharge space, a first electrode provided on the first substrate side, and a second electrode provided on the second substrate side. A transparent insulating layer covering the second electrode, the first electrode so that the first and second electrodes do not overlap.
The second electrode is displaced with respect to the first substrate, and is located on the opposite side of the first substrate from the discharge space side.
The first electrode is disposed on the outer surface of the second substrate, and the first electrode is disposed on the surface of the second substrate on the discharge space side.
A discharge light emitting device in which two electrodes are arranged and the first electrode is set to a ground potential . 5. The insulating layer is provided with an opening reaching the second substrate, and the second substrate is provided on the surface of the second substrate located in the opening.
The discharge light-emitting device according to claim 4 , wherein a phosphor is formed. 6. A first substrate, a discharge space into which a discharge gas is sealed between the first substrate
Is formed on the first substrate so as to form a transparent film.
A second substrate, first and second phosphors installed in the discharge space, a first electrode provided on the first substrate side, and a second electrode provided on the second substrate side. the provided, such that the first and second electrodes do not overlap, the first electrode
A discharge light emitting device in which the second electrode is arranged so as to be offset with respect to the first electrode, the first electrode has a flat plate shape, and the second electrode has a ring shape . Is characterized by using as 7. The light source for the contact image sensor, the discharge light emitting device according to any one of claims 1 to 6.